Underclassmen have made a huge impact on the NFL Draft over the past two decades, and this spring younger players will once again have a strong presence in the Draft - especially in the early rounds.

Underclassmen have until Jan. 15 to declare for the 2008 Draft. The players will then have three additional days to change their minds. Anywhere from 30 to 50 prospects each season forego their remaining college eligibility to enter the draft.

To help the players make informed decisions, the NFL has provided an experienced advisory committee that evaluates underclassmen and gives players an idea where they might be selected. The estimation is based on evaluation by NFL scouts, but it is only their subjective opinion.

Below, Rivals.com NFL Draft partner Frank Coyle of draftinsiders.com gives his evaluations of several dozen underclassmen who may be considering entering the Draft.

(* - Denotes redshirt sophomore. Players must be three years removed from high school to be eligible for the NFL Draft.)

This very productive junior wideout set an SEC record for career receptions. He has the ability to be a legitimate deep threat as a pro. He could challenge for the top spot at the position with a strong postseason.

Rare 2,000-yard rusher has natural running skills and a high level of development that will entice him to turn pro. If he receives a top-50 grade from the advisory committee, he'll likely join the NFL.

This fast edge pass rusher has been a force this season. He has been one of the premier sack artists in the nation. A third-year sophomore, he has the growth potential to fill out further and improve in run support.

Frank Coyle is a nationally known NFL scout who publishes Draft Insiders' Digest and www.draftinsiders.com. Draft Insiders' Digest is dedicated to year-round coverage of NFL and NCAA Football. Coyle covers the NFL Draft and free agency extensively with a veteran scouting staff that provides insightful and unique information on players and team potential in the coming seasons. Draft Insiders' Digest is an extensive publication that produces more than 20 issues throughout the year, beginning with an Online Pro Prospects Preview and Fantasy Football Rankings in August and a 200-page Draft Yearbook in March.